Merge pull request #10 from sheharyarn/bugfix/mnesia-cyclic-exits

Fix Mnesia's Cyclic Exits

Author: sheharyarn

README.md

@@ -63,7 +63,7 @@ Add `:memento` to your list of dependencies in your Mix file:
 
 ```elixir
 def deps do
-  [{:memento, "~> 0.2.1"}]
+  [{:memento, "~> 0.3.0"}]
 end
 ```
 

lib/memento/mnesia.ex

@@ -14,6 +14,23 @@ defmodule Memento.Mnesia do
 
   @doc "Call an Mnesia function"
   defmacro call(method, arguments \\ []) do
+    quote(bind_quoted: [fun: method, args: arguments]) do
+      apply(:mnesia, fun, args)
+    end
+  end
+
+
+
+  @doc """
+  Call an Mnesia function and catch any exits
+
+  Should ONLY be used with transaction methods, because catching
+  exits inside transactions seriously impacts the performance of
+  Mnesia.
+
+  Reference: https://github.com/sheharyarn/memento/issues/2
+  """
+  defmacro call_and_catch(method, arguments \\ []) do
     quote(bind_quoted: [fun: method, args: arguments]) do
       require Memento.Error
 

lib/memento/schema.ex

@@ -66,7 +66,7 @@ defmodule Memento.Schema do
     end
 
     :create_schema
-    |> Memento.Mnesia.call([nodes])
+    |> Memento.Mnesia.call_and_catch([nodes])
     |> Memento.Mnesia.handle_result
   end
 
@@ -83,7 +83,7 @@ defmodule Memento.Schema do
   @spec delete(list(node)) :: :ok | {:error, any}
   def delete(nodes) do
     :delete_schema
-    |> Memento.Mnesia.call([nodes])
+    |> Memento.Mnesia.call_and_catch([nodes])
     |> Memento.Mnesia.handle_result
   end
 
@@ -96,7 +96,7 @@ defmodule Memento.Schema do
   @spec info() :: :ok
   def info do
     :schema
-    |> Memento.Mnesia.call
+    |> Memento.Mnesia.call_and_catch
     |> Memento.Mnesia.handle_result
   end
 
@@ -109,7 +109,7 @@ defmodule Memento.Schema do
   @spec info(Memento.Table.name) :: :ok
   def info(table) do
     :schema
-    |> Memento.Mnesia.call([table])
+    |> Memento.Mnesia.call_and_catch([table])
     |> Memento.Mnesia.handle_result
   end
 

lib/memento/transaction.ex

@@ -68,7 +68,7 @@ defmodule Memento.Transaction do
   @spec execute(fun, retries) :: {:ok, any} | {:error, any}
   def execute(function, retries \\ :infinity) do
     :transaction
-    |> Memento.Mnesia.call([function, retries])
+    |> Memento.Mnesia.call_and_catch([function, retries])
     |> Memento.Mnesia.handle_result
   end
 
@@ -102,7 +102,7 @@ defmodule Memento.Transaction do
   @spec execute_sync(fun, retries) :: {:ok, any} | {:error, any}
   def execute_sync(function, retries \\ :infinity) do
     :sync_transaction
-    |> Memento.Mnesia.call([function, retries])
+    |> Memento.Mnesia.call_and_catch([function, retries])
     |> Memento.Mnesia.handle_result
   end
 

mix.exs

@@ -3,7 +3,7 @@ defmodule Memento.Mixfile do
 
   @app     :memento
   @name    "Memento"
-  @version "0.2.1"
+  @version "0.3.0"
   @github  "https://github.com/sheharyarn/#{@app}"
   @author  "Sheharyar Naseer"
   @license "MIT"

test/memento/mnesia_test.exs

@@ -7,6 +7,14 @@ defmodule Memento.Tests.Mnesia do
 
 
   describe "#call" do
+    test "delegates method calls to the mnesia module" do
+      assert :yes == Mnesia.call(:system_info, [:is_running])
+    end
+  end
+
+
+
+  describe "#call_and_catch" do
     setup do
       Support.Mnesia.stop
       :ok
@@ -16,15 +24,15 @@ defmodule Memento.Tests.Mnesia do
     @func :system_info
     @args [:is_running]
     test "delegates method calls to the mnesia module" do
-      assert :no == Mnesia.call(@func, @args)
+      assert :no == Mnesia.call_and_catch(@func, @args)
     end
 
 
     @func :schema
     @args []
     test "re-raises mnesia exits as memento exceptions" do
       assert_raise(MnesiaException, ~r/not running/i, fn ->
-        Mnesia.call(@func, @args)
+        Mnesia.call_and_catch(@func, @args)
       end)
     end
 
@@ -33,7 +41,7 @@ defmodule Memento.Tests.Mnesia do
     @args [Tables.User, :all]
     test "prints descriptions of the error" do
       assert_raise(MnesiaException, ~r/tried to perform op on non-existing/i, fn ->
-        Mnesia.call(@func, @args)
+        Mnesia.call_and_catch(@func, @args)
       end)
     end
   end

test/support/support.ex

@@ -29,6 +29,10 @@ defmodule Memento.Support do
     end
 
 
+    def transaction(fun) when is_function(fun) do
+      Memento.Transaction.execute(fun)
+    end
+
     def transaction({module, method, args})
     when is_atom(module) and is_atom(method) do
       transaction(fn ->
@@ -43,10 +47,5 @@ defmodule Memento.Support do
       end)
     end
 
-
-    def transaction(fun) when is_function(fun) do
-      Memento.Transaction.execute(fun)
-    end
-
   end
 end